One vertex per element, one color per generator, with an edge from x to x·s.
(3,7)(5,8)(12,20)(16,21)(18,24)(22,23)(25,26,31,32)(27,28,35,40)(29,33,30,34)(36,38,37,39)(1,2,4,6)(3,8,7,5)(9,10)(11,17)(12,16)(13,14)(15,19)(18,23)(20,21)(22,24)(26,32)(27,35)(33,34)(36,37)(1,3,4,7)(2,5,6,8)(10,14)(15,17)(16,21)(22,23)(25,27)(26,28)(29,36)(30,37)(31,35)(32,40)(33,38)(34,39)(1,2)(3,5)(4,6)(7,8)(9,10)(11,15)(12,16)(13,14)(17,19)(18,22)(20,21)(23,24)(25,28)(26,27)(29,38)(30,39)(31,40)(32,35)(33,36)(34,37) involution — undirected(9,11,13,19)(10,15,14,17)(12,18,20,24)(16,22,21,23)(25,29,31,30)(26,33,32,34)(27,36,35,37)(28,38,40,39)(9,12)(10,16)(11,18)(13,20)(14,21)(15,22)(17,23)(19,24)(25,30,31,29)(26,34,32,33)(27,37,35,36)(28,39,40,38)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.